The OT is full of stories of battle and the judgment of God. As you read 1 and 2 Samuel, 1 and 2 Kings, 1 and 2 Chronicles, Judges, Lamentations, Joshua, and other books in the Old Testament, we see an extraordinary amount of blood and gore, judgment from God on those who are His enemies. Entire Canaanite nations are destroyed, armies wiped off the map, kings brought down. The power of God is on full display in the OT, the showcase being His enemies.
If you believe the Bible to be a factual account of history and of God, it is impossible to walk away from it not realizing the magnificent strength and power of God. His judgment on those who stand against Him is ample evidence of the potential of His fury when His mercy comes to an end.
In order to fully grasp the enormity of the statement that "God is love", we need to first grasp the concept that God has enormous potential for wrath, completely deserved wrath, toward His creation. In our sin, we deserve the wrath of God, not His love. The New Testament is the story of God's anger being poured out on Jesus Christ so we could experience His love instead of His fury.
In order to properly understand God's nature (to the extent we can as humans), we cannot ignore His wrath demonstrated in the OT or the hatred He claims for the wicked (Ps. 11:5), nor can we ignore His love (Eph. 2:4-5). Both are equally important facets of His nature. We don't realize His love is as beautiful as it is until we realize that our natural state is under His judgment.
God is anger toward sin and compassion toward sinners walking hand in hand. Without seeing both these facets of His nature, we miss a pivotal part of who God is. In His perfection, He balances two seeming opposites to form His ultimate holiness.
In trying to know Christ better, it's pivotal that we ignore neither of these sides of God. In order to properly present Christ we must not present Him as the furious judge of the world, waiting with Thor's hammer for you to step out of line so He can smash you to the dust. He is also not a cosmic teddy bear, responding to sin with grandmotherly affection.
Both for the sake of presenting the gospel to others and for gaining a better understanding of Him for yourself, both these attributes need to be considered. A proper, Biblical understanding of the gospel cannot exist without a statement of both parts of His nature. His grace and mercy is only understood in relation to the anger we deserve; yet a single-focused look at His anger leaves us standing trembling in fear before a God who desires to be our Father.
I admit, the idea of God as a lovey-dovey grandmotherly figure in the sky can be attractive. My encouragement to you, though, is to see God for who He says He is. God is love. But God is also wrath. God is mercy. But God is just. God is patient. But God is Judge.
Why do I spend time presenting this? What's the point? The point is to examine God for who He is, not for who we want Him to be. He is far too great a God to be locked in the box of our preconceived notions of Him. In studying the entire nature of God rather than simply the attributes we would prefer Him to have, we avoid the dangerous imbalance of seeing God in the light of my human desires and preferences rather than as an "unwieldy mystery" as Brennan Manning put it.
When we look at the immense fury of God, then we can properly see the magnitude of His mercy on us. And in looking at His complete character rather than snippets, we see a more complete image of the gospel rather than simply the concepts and ideas that immediately appeal to our senses. God is God; His character is already fixed. Our goal is to find more and more about Him, not to conform Him to the image I would prefer Him to be.